Merge tag 'trace-rv-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull runtime verification updates from Steven Rostedt:

 - Added Linear temporal logic monitors for RT application

   Real-time applications may have design flaws causing them to have
   unexpected latency. For example, the applications may raise page
   faults, or may be blocked trying to take a mutex without priority
   inheritance.

   However, while attempting to implement DA monitors for these
   real-time rules, deterministic automaton is found to be inappropriate
   as the specification language. The automaton is complicated, hard to
   understand, and error-prone.

   For these cases, linear temporal logic is found to be more suitable.
   The LTL is more concise and intuitive.

 - Make printk_deferred() public

   The new monitors needed access to printk_deferred(). Make them
   visible for the entire kernel.

 - Add a vpanic() to allow for va_list to be passed to panic.

 - Add rtapp container monitor.

   A collection of monitors that check for common problems with
   real-time applications that cause unexpected latency.

 - Add page fault tracepoints to risc-v

   These tracepoints are necessary to for the RV monitor to run on
   risc-v.

 - Fix the behaviour of the rv tool with -s and idle tasks.

 - Allow the rv tool to gracefully terminate with SIGTERM

 - Adjusts dot2c not to create lines over 100 columns

 - Properly order nested monitors in the RV Kconfig file

 - Return the registration error in all DA monitor instead of 0

 - Update and add new sched collection monitors

   Replace tss and sncid monitors with more complete sts:

   Not only prove that switches occur in scheduling context and scheduling
   needs interrupt disabled but also that each call to the scheduler
   disables interrupts to (optionally) switch.

   New monitor: nrp
     Preemption requires need resched which is cleared by any switch
     (includes a non optimal workaround for /nested/ preemptions)

   New monitor: sssw
     suspension requires setting the task to sleepable and, after the
     switch occurs, the task requires a wakeup to come back to runnable

   New monitor: opid
      waking and need-resched operations occur with interrupts and
      preemption disabled or in IRQ without explicitly disabling
      preemption"

* tag 'trace-rv-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (48 commits)
  rv: Add opid per-cpu monitor
  rv: Add nrp and sssw per-task monitors
  rv: Replace tss and sncid monitors with more complete sts
  sched: Adapt sched tracepoints for RV task model
  rv: Retry when da monitor detects race conditions
  rv: Adjust monitor dependencies
  rv: Use strings in da monitors tracepoints
  rv: Remove trailing whitespace from tracepoint string
  rv: Add da_handle_start_run_event_ to per-task monitors
  rv: Fix wrong type cast in reactors_show() and monitor_reactor_show()
  rv: Fix wrong type cast in monitors_show()
  rv: Remove struct rv_monitor::reacting
  rv: Remove rv_reactor's reference counter
  rv: Merge struct rv_reactor_def into struct rv_reactor
  rv: Merge struct rv_monitor_def into struct rv_monitor
  rv: Remove unused field in struct rv_monitor_def
  rv: Return init error when registering monitors
  verification/rvgen: Organise Kconfig entries for nested monitors
  tools/dot2c: Fix generated files going over 100 column limit
  tools/rv: Stop gracefully also on SIGTERM
  ...

1 files changed, 9 insertions, 6 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 40d2fa90df42..a9693f179c58 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -340,9 +340,11 @@ extern void io_schedule_finish(int token);
 extern long io_schedule_timeout(long timeout);
 extern void io_schedule(void);
 
-/* wrapper function to trace from this header file */
+/* wrapper functions to trace from this header file */
 DECLARE_TRACEPOINT(sched_set_state_tp);
 extern void __trace_set_current_state(int state_value);
+DECLARE_TRACEPOINT(sched_set_need_resched_tp);
+extern void __trace_set_need_resched(struct task_struct *curr, int tif);
 
 /**
  * struct prev_cputime - snapshot of system and user cputime
@@ -1634,12 +1636,10 @@ struct task_struct {
 
 #ifdef CONFIG_RV
 	/*
-	 * Per-task RV monitor. Nowadays fixed in RV_PER_TASK_MONITORS.
-	 * If we find justification for more monitors, we can think
-	 * about adding more or developing a dynamic method. So far,
-	 * none of these are justified.
+	 * Per-task RV monitor, fixed in CONFIG_RV_PER_TASK_MONITORS.
+	 * If memory becomes a concern, we can think about a dynamic method.
 	 */
-	union rv_task_monitor		rv[RV_PER_TASK_MONITORS];
+	union rv_task_monitor		rv[CONFIG_RV_PER_TASK_MONITORS];
 #endif
 
 #ifdef CONFIG_USER_EVENTS
@@ -2030,6 +2030,9 @@ static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
 
 static inline void set_tsk_need_resched(struct task_struct *tsk)
 {
+	if (tracepoint_enabled(sched_set_need_resched_tp) &&
+	    !test_tsk_thread_flag(tsk, TIF_NEED_RESCHED))
+		__trace_set_need_resched(tsk, TIF_NEED_RESCHED);
 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
 }